Experimental study of compact sandstone deformation under axisymmetric triaxial loading along specific paths in stress space

0577482 - ÚGN 2024 RIV DE eng J - Journal Article
Janeček, Ivan - Mishra, A. Deepak - Vishnu, C. S. - Ščučka, Jiří - Vaculíková, Lenka - Martinec, Petr
Experimental study of compact sandstone deformation under axisymmetric triaxial loading along specific paths in stress space.
Rock Mechanics and Rock Engineering. Roč. 57, č. 1 (2023), s. 97-113. ISSN 0723-2632. E-ISSN 1434-453X
R&D Projects: GA MŠMT(CZ) LO1406; GA MŠMT(CZ) LM2015084; GA ČR GA18-25035S
Grant - others:GA MŠk(CZ) EF16_013/0001792
Institutional support: RVO:68145535
Keywords : rock mechanics * triaxial stress state * Young’s modulus * Poisson’s ratio * rock isotropy * sedimentary rocks * sandstone
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 6.2, year: 2022
Method of publishing: Open access
https://link.springer.com/article/10.1007/s00603-023-03581-z

The deformation of rocks well below their ultimate strengths is frequently described through the constant stiffness moduli of the linear elasticity theory. In addition, the isotropic material approximation is usually used as the basic approach. Particularly in sedimentary rocks, local inhomogeneities, anisotropy, and irreversible processes, mainly related to the gradual breakage of grain joints, can affect their deformation behavior from the beginning of the loading. Consequently, the stiffness moduli measured under triaxial conditions are effective parameters, which may depend on the loading path in the stress space. Therefore, a complex experimental study of the deformation response of compact sedimentary rock (Brenna sandstone) along various paths in triaxial stress space was prepared to understand this dependence. In addition, a detailed analysis of the rock composition and structure of this compact sandstone was carried out. This paper presents an initial experimental study that is based on a loading method using alternative stress paths that correspond to different modes of the monotonic increase in differential stress from an initial isotropic compression state. In the experiment, the dependence of stiffness moduli on the loading path was found. Differences in rock deformation for conventional triaxial compression and extension can be attributed to a slight rock anisotropy originating from the stratification. The different behavior of deformation and related stiffness moduli along so-called reduced triaxial paths and conventional paths indicates that irreversible processes must be taken into account.
Permanent Link: https://hdl.handle.net/11104/0346615